MINOR: tools: provide a may_access() function and make dump_hex() use it
It's a bit too easy to crash by accident when using dump_hex() on any
area. Let's have a function to check if the memory may safely be read
first. This one abuses the stat() syscall checking if it returns EFAULT
or not, in which case it means we're not allowed to read from there. In
other situations it may return other codes or even a success if the
area pointed to by the file exists. It's important not to abuse it
though and as such it's tested only once per output line.
diff --git a/include/common/standard.h b/include/common/standard.h
index 6fb1c94..0bea022 100644
--- a/include/common/standard.h
+++ b/include/common/standard.h
@@ -1423,7 +1423,8 @@
int dump_binary(struct buffer *out, const char *buf, int bsize);
int dump_text_line(struct buffer *out, const char *buf, int bsize, int len,
int *line, int ptr);
-void dump_hex(struct buffer *out, const char *pfx, const void *buf, int len);
+void dump_hex(struct buffer *out, const char *pfx, const void *buf, int len, int unsafe);
+int may_access(const void *ptr);
/* same as realloc() except that ptr is also freed upon failure */
static inline void *my_realloc2(void *ptr, size_t size)